Do you think, hauling around an extra 600lbs, the hit on your mpg, it actually saves money?

2015 RAM 3500 CCSB CUMMINS
2016 Sabre 36QBOK

I don't see ANY difference in mpg with the transfer tank full anymore than having the stock tank full. If there is any difference, it's minuscule and no big deal, certainly not .50 a gallon lose. And yes I do KNOW it's saving me money.

I don't see ANY difference in mpg with the transfer tank full anymore than having the stock tank full. If there is any difference, it's minuscule and no big deal, certainly not .50 a gallon lose. And yes I do KNOW it's saving me money.

But at $1000, how long would it take to pay for itself?

Are you saving that 50c every fill?
How far out of your way do you have to go to save that 50c?

You may want to check with your Dodge dealer as to the availability of "saddle tanks". Most brands have optional onboard aux tanks, but they are REALLY pricey! They mount under the bed of the truck and use a switch to transfer.
When I bought my truck, I looked into the option, but way too expensive over the bed tank.

Are you saving that 50c every fill?
How far out of your way do you have to go to save that 50c?

Actually, it was around $650. I don't go a mile out of my way to any FlyingJ/Pilot or any other truckstops, they line the highways everywhere I go. With the extra fuel onboard, I have the option to buy when/where I want. If I don't like the price, I just keep on trucking
I usually fill up when I'm down around 15-20 gallons IF THE LOCAL PRICE IS RIGHT. At a .50 a gallon savings, that around $35 per fill up saved and more important to me is I will have enough fuel to get home in an emergency, ie electrical power lose from floods or hurricanes, etc. Been there, done that. That will never happen to me again.
And probably the best reason I have the extra tank is because I like it that way. That's why they race horses! And I'm not looking for it to pay for itself. Never did.

I had my Ford dealer install a 90 gallon RDS from Northern Tool on my former 2011 F450. It sat flush with the top of the bed and did not interfere with our fifth wheel hitch at all. It was 90 gallons of diesel with a free flowing line feeding into the filler neck of my truck's tank. It had a petcock in the line so I could either turn it off or run with it flowing while driving down the road. 125 gallons of fuel at a time.

It sticks up around 3" above the bed line but takes up less bed space. I don't have a fifth wheel now but I ordered this tank with the assumption it should still be OK regarding fifth wheel clearance but even more bed space. I have the same set-up regarding fuel flow and think its a perfect way to go. In my opinion, having a transfer pump is just a waste of money.

The only negative to this tank is it really won't hold a full 90 gallons. 85 gallons at the most but that's still pretty good.

By the way, both of these tanks I listed have tool boxes on the top. The lid also locks down and the cap locks as well so anyone messing with your fuel would have to get through two locks to do so.

Are you saving that 50c every fill?
How far out of your way do you have to go to save that 50c?

I didn't purchase mine with the idea it would pay for itself in fuel savings.. I bought it for the convenience of driving all day pulling a 5er without thinking of the next fuel stop.

I'm also partial to buying fuel only at places that sell a lot of diesel fuel. I made that mistake once years ago buying fuel at a small station where they didn't sell enough of it so I got summer fuel in the fall and it got cold so there I sat with gelled fuel in the tank.

I did not buy my 100 gal fuel tank to really save any money, I got it mostly for convenience. I have a gas card that I use to buy diesel and it has to be swiped for me to get my discount. I can't use it at truck stops, it's 5% so it does add up. But I don't really save any money. I went last month to Myrtle Beach and the difference I paid for fuel paid my way there and back, not pulling a camper

Are you saving that 50c every fill?
How far out of your way do you have to go to save that 50c?

My tank and the installation kit cost around $650.00. I will probably never get all that back and I'm on my second truck with this tank installed...Then on the other hand staying in my fifth wheel about 100 nights a year will never cost less than staying in a motel once you figure in the cost of renting a space at an RV park, fuel, electricity and oh yea...the cost of the fifth wheel. Don't have that to save money either...